It is a well known principle that introduction of humidity into a dry atmosphere lowers the ambient atmospheric temperature. Evaporative or “swamp” coolers served as effective refrigeration devices in desert climates for over fifty years. This principle has been applied in the development of devices to cool a more localized area by spraying a fine mist. Such devices are known in the art and an examination of these devices reveals that the water is pressurized by motor power, by attachment to a tank of pressurized gas, or by manual pumping. The motor-powered sprayers tend to be heavy, noisy, and cumbersome to use, and require fuel or an electrical cord connecting the sprayer to an electrical source. The air-pressurized sprayers require that the user has constant access to a source of pressurized air to recharge the container. These limitations severely inhibit the convenience and portability of the spraying apparatus.
Manually-pumped containers eliminate the requirement for a separate source of pressurization and enabled the development of portable misting systems. In essence, a hand-pump is directly attached to a small water tank, and the user manually reciprocates the pump handle to force air into the tank to pressurize it. The device is turned on by opening a flow valve, and a fine mist is emitted from a nozzle. However, in the prior art devices, the user could not tell if the container was sufficiently pressurized to emit a fine mist without testing it by opening the valve. A container that is insufficiently pressurized would release large drops of water slowly, often dripping big drops, rather than spraying a fine mist. Insufficient pressure therefore renders the apparatus useless for its purpose because the emission isn't a mist and, moreover, it is also messy. It would be desirable to know the amount of pressure inside the container before the valve is opened. Then, if the pressure is too low to create a mist, the container could be pressurized to a sufficient level before it is turned on, avoiding drips.
In previously disclosed portable devices, the flow of mist is controlled by a flow valve connected by a plastic tube to the outside of the tank at a water outlet. Usually the connections between the tank, flow valve and tube are friction fit. That is, the flow valve just squeezes into the end of the tube and the nozzle squeezes into the end of the flow control valve, all held in place by the friction. The distance between the flow valve and the water container makes it easy to snag the flow valve or nozzle and accidentally pull one off. This is especially a problem with portable misting devices. Further, when the nozzle is detached from the apparatus, the flow valve remains connected and will still release water if opened. Without a misting nozzle on the end, essentially a stream of water is released. This, again, is especially a problem with portable misting devices because the valve could be accidentally opened during transportation and cause the water to leak out. To increase the durability of a portable mister, it would be beneficial to provide a flow valve assembly that is more durable.
A similar problem plagues the known portable misting devices with the pump handle. The handle extends form the water container a sufficient distance to make the knob on the handle easy to grasp. Unfortunately, this extension makes it easy to snag the knob and accidentally pull out the handle, making the device bigger and unwieldy, and again making storage and transportation inconvenient and messy.
Therefore, it is an object of this invention to provide an apparatus which utilizes the evaporative cooling principle in a device that is more durable and less messy than those of the prior art. It is another object of this invention to integrate the flow valve assembly and handle into the device. It is another object to provide a misting device that minimizes the risk of water leaking out as a fluid, instead of spraying out as a mist.